8 is the latest approved patch-set.
No files were changed between the latest approved patch-set and the submitted one.


ASCI: Increase channel request history to 5 entries

3 entries are enough for random access on CCCH. 5 are required for
uplink request on VGCS channel.

The history is used to remember when the random access bursts were send.
The RR layer can check if the IMMEDIATE ASSIGNMENT or VGCS UPLINK GRANT
message has matching frame number and random value of up to 5 random
access bursts previously sent.

Related: OS#5364
Change-Id: I62f18685bf05663f3ee6e94f6884ffb9a6b07ea4
---
M src/host/layer23/include/osmocom/bb/mobile/gsm48_rr.h
M src/host/layer23/src/mobile/gsm48_rr.c
2 files changed, 31 insertions(+), 15 deletions(-)

diff --git a/src/host/layer23/include/osmocom/bb/mobile/gsm48_rr.h b/src/host/layer23/include/osmocom/bb/mobile/gsm48_rr.h
index 299b6e5..fb07cc9 100644
--- a/src/host/layer23/include/osmocom/bb/mobile/gsm48_rr.h
+++ b/src/host/layer23/include/osmocom/bb/mobile/gsm48_rr.h
@@ -159,7 +159,7 @@
 
 	/* cr_hist */
 	uint8_t			cr_ra; /* stores requested ra until confirmed */
-	struct gsm48_cr_hist	cr_hist[3];
+	struct gsm48_cr_hist	cr_hist[5];
 
 	/* V(SD) sequence numbers */
 	uint16_t		v_sd; /* 16 PD 1-bit sequence numbers packed */
diff --git a/src/host/layer23/src/mobile/gsm48_rr.c b/src/host/layer23/src/mobile/gsm48_rr.c
index 835e48c..817c886 100644
--- a/src/host/layer23/src/mobile/gsm48_rr.c
+++ b/src/host/layer23/src/mobile/gsm48_rr.c
@@ -84,6 +84,9 @@
 
 #include <l1ctl_proto.h>
 
+/* Check response for the last 3 channel requests only. See TS 44.018 §3.3.1.1.3.1 and §3.3.1.1.3.2. */
+#define IMM_ASS_HISTORY		3
+
 static void start_rr_t_meas(struct gsm48_rrlayer *rr, int sec, int micro);
 static void stop_rr_t_starting(struct gsm48_rrlayer *rr);
 static void stop_rr_t3124(struct gsm48_rrlayer *rr);
@@ -1489,12 +1492,10 @@
 		return -EINVAL;
 	}
 
-	/* store value, mask and history */
+	/* store value, mask and clear history */
 	rr->chan_req_val = chan_req_val;
 	rr->chan_req_mask = chan_req_mask;
-	rr->cr_hist[2].valid = 0;
-	rr->cr_hist[1].valid = 0;
-	rr->cr_hist[0].valid = 0;
+	memset(rr->cr_hist, 0, sizeof(rr->cr_hist));
 
 	/* store establishment cause, so 'choose cell' selects the last cell
 	 * after location updating */
@@ -1545,10 +1546,7 @@
 		}
 
 		/* shift history and store */
-		memcpy(&(rr->cr_hist[2]), &(rr->cr_hist[1]),
-			sizeof(struct gsm48_cr_hist));
-		memcpy(&(rr->cr_hist[1]), &(rr->cr_hist[0]),
-			sizeof(struct gsm48_cr_hist));
+		memmove(rr->cr_hist + 1, rr->cr_hist, sizeof(rr->cr_hist) - sizeof(rr->cr_hist[0]));
 		rr->cr_hist[0].valid = 1;
 		rr->cr_hist[0].ref.ra = rr->cr_ra;
 		rr->cr_hist[0].ref.t1 = ref->t1;
@@ -2364,14 +2362,14 @@
  */
 
 /* match request reference against request history */
-static int gsm48_match_ra(struct osmocom_ms *ms, struct gsm48_req_ref *ref)
+static int gsm48_match_ra(struct osmocom_ms *ms, struct gsm48_req_ref *ref, uint8_t hist_num)
 {
 	struct gsm48_rrlayer *rr = &ms->rrlayer;
 	int i;
 	uint8_t ia_t1, ia_t2, ia_t3;
 	uint8_t cr_t1, cr_t2, cr_t3;
 
-	for (i = 0; i < 3; i++) {
+	for (i = 0; i < hist_num; i++) {
 		/* filter confirmed RACH requests only */
 		if (rr->cr_hist[i].valid && ref->ra == rr->cr_hist[i].ref.ra) {
 		 	ia_t1 = ref->t1;
@@ -2492,7 +2490,7 @@
 	}
 
 	/* request ref */
-	if (gsm48_match_ra(ms, &ia->req_ref)) {
+	if (gsm48_match_ra(ms, &ia->req_ref, IMM_ASS_HISTORY)) {
 		/* channel description */
 		memcpy(&rr->cd_now, &cd, sizeof(rr->cd_now));
 		/* timing advance */
@@ -2640,7 +2638,7 @@
 	}
 
 	/* request ref 1 */
-	if (gsm48_match_ra(ms, &ia->req_ref1)) {
+	if (gsm48_match_ra(ms, &ia->req_ref1, IMM_ASS_HISTORY)) {
 		/* channel description */
 		memcpy(&rr->cd_now, &cd1, sizeof(rr->cd_now));
 		/* timing advance */
@@ -2656,7 +2654,7 @@
 		return gsm48_rr_dl_est(ms);
 	}
 	/* request ref 2 */
-	if (gsm48_match_ra(ms, &ia->req_ref2)) {
+	if (gsm48_match_ra(ms, &ia->req_ref2, IMM_ASS_HISTORY)) {
 		/* channel description */
 		memcpy(&rr->cd_now, &cd2, sizeof(rr->cd_now));
 		/* timing advance */
@@ -2706,7 +2704,7 @@
 				(((uint8_t *)&ia->req_ref1) + i * 4);
 		LOGP(DRR, LOGL_INFO, "IMMEDIATE ASSIGNMENT REJECT "
 			"(ref 0x%02x)\n", req_ref->ra);
-		if (gsm48_match_ra(ms, req_ref)) {
+		if (gsm48_match_ra(ms, req_ref, IMM_ASS_HISTORY)) {
 			/* wait indication */
 			t3122_value = *(((uint8_t *)&ia->wait_ind1) + i * 4);
 			if (t3122_value)

